Azo dyestuffs, etc.



UNITED STATES PATENT OFFICE AZO nrnsrurrs, arc.

Bernard Herstein, Brooklyn, N. Y., assignor to U. S. Industrial AlcoholCompany, New York, N. Y., a corporation of West Virginia No Drawing.Application August 11, 1937, Serial No. 158,475

17 Claims. (Oi. 8-50) This invention relates to new dyestufis and toreaction is completed the solution is filtered if methods of producingthe same and to the dyeing necessary. The diazo solution is then addedto of cellulose acetate therewith. a cold solution of 20 lbs. (2 lbs.excess) of the a The new azo dyestuffs are made by coupling sodio saltof ethyl acetyl pyruvate b g a dlazotized para-substitutedortho-nitranilin, substituted in para position by chlorine or a(CH3C(ON9{) 'C methyl group with alkyl esters of acids such as in about110 gallons of water, to which sufilcient acetoneoxanc and oxal'aceticThe sodium acetate is added to counteract the delestitutedortho-nitranilin compounds have the terious fl' t f the mineral acid Ngeneralformula The coupled suspension should be agitated for about '30minutes, then filtered, and the dye washed thoroughly with cold water.Air drying Q givesa finely divided bright yellow body of 2- 35 where Xis a member of the group consisting of 23 g gfi benzol. azo acetoneoxalic acid chlorine and y The new dyestuffs m The reaction involved inthe production of the eral can be considered to have the following newdyestufl, and a graphic representation of formula: R N=N 'R1' where R isthe residue the formula of the new dyestufi in its tautomeric of thediazotized ortho-nitranilin compound and wmodiflcaflons is illustratedby the following R1 is theresidue of the alkyl ester of an acidequation. 20

such as acetone-oxalic acid or oxal-acetic acid.

Thesenew dyestuffs are particularly advantage- CH3C(QNa):CHCOCOOEt+ClN:NCtH4NOiCHa ous for dyeing cellulose acetate.

' The alkyl esters of the acids used in making 5!wethyl'acetylpymmte gfgggg new dyestufls are readily obtainable for example I 25 by theso-called Claisen condensation by con- CH'OOCOOCOOE F densing the properesters, or an ester and ketone, -.-i I +NaCl with the use of metallicsodium or sodium alkox- EN 0 iHlNQiCHi NCOHGNOICH8 lde with theresulting production of alkyl esters2-nltro-4-metllyl-benzol-azo-acetone-oxalic acid ethyl ester so of sodioacids; and these intermediate sodio comp unds of the compoun whsufficiently Stable. ExAmPLr: II.--Azo dyestufl from m-m'tro-p-toluiareadv'a tas sly used, without first 18018151118 dine and ethylsodio-ozal-acetate the esters of the acids, for coupling with thediazonium chloride which results from the diazo--Meta-nitro-pll'a-toluldine is diazotized as nation v the meta-n1tropara-to]u1d1ne scribed in the preceding example and the diazo Thealkylesters of the acid u d i maki solution is similarly added to a coldsolution of the new dyestuirs include methyl, ethyl and other ethyl s da ta using an q v n 'alkyl esters of acids such as alkyl acetonequantityto the quantity of ethyl so'dio acetyl oxalates and alkyl oxal-acetates.pyruvate in Example I.

40 The invention will be further l rated by the The reaction and thegraphically represented 40 following specific examples, but it isintended and formula of the product in its tautomeric modifiwill beunderstoodthat the invention is not limcations are indicated by thefollowing equation: ited thereto: v I Nor Exunul I.Azo duestufl fromm-nitro-p-toluidin nd ethlll sodio-aeetone-oxalat'e'clmooccmcwmwoocmwmm-O-om Meta-nitro-para-toluidine (15.2 lbs.) isdiazotized by suspending it in 12 gallons of ice-cooled I watercontaining 30.6 lbs. concentrated H01 N ii (sp. gr. 1.19). Aconcentrated aqueous solution 1 50 of sodium nitrite ('1 lbs.) is thenadded with no. Newman CIHIOOCCH-COCOOCIHI Ci- IQOCCOQCOOCiHI stirringand cooling until a permanent positive test for free nitrous acid isobtained with potassium iodide starch paper. The temperature of u thediazo solution is kept at 0-5 C. When the EXAMPLES III and IV.Azodyestufis from pchZor-o-nitranilin Para-chlor-ortho-nitranilin isdiazotized in a manner similar to that described in Example I for thediazotization of meta-nitro-para-toluidine, using 17.3 lbs. of thep-chlor-o-nitranilin instead of 15.2 lbs of the m-nitro-p-toluidine, andthe resulting diazo solution is then added to a cold solution of thealkyl ester of the acid used in a manner similar to that described inthe above examples. That is, the diazo solution is added to a coldsolution of the sodio salt of ethyl acetyl pyruVate or to a coldsolution of ethyl sodio-oxal-acetate, in a manner similar to thatdescribed in the above examples and giving dyes of similar compositionbut containing chlorine instead of the methyl group in para position inthe nitranilin residue.

In the above examples the ethyl esters are used in each case but similarresults canbe obtained with the methyl or other esters. Although theabove examples refer to the use of the sodio compounds of the alkylesters of acetone-oxalic and oxal-acetic acids, it is to be understoodthat the free esters, i. e., the non-sodio compounds, may also be usedin preparing the new dyestuffs, the procedure when using these compoundsbeing the same as with the sodio compounds.

Where the intermediate sodio-compounds of the alkyl esters of the acidsused are stable, these intermediates are advantagously used, withoutisolation of the free ester, as illustrated in the examples above. Inthis case the combination or coupling is between the intermediate andthe diazonium chloride. In proceeding in this way, the isolation of theester is unnecessary and the intermediate sodio compound is directlyused for coupling with the diazonium chloride in making the dyestufi.

The new azo dyestuffs are particularly advantageous, as above stated,for dyeing cellulose acetate and appear to be specific for celluloseacetate fibers and fabrics. They do not 'dye either cotton or viscoseand, if they dye silk or wool at all, the materials so dyed are veryunstable toward soap solutions.

Cellulose acetat' is readily dyed with the new dyestufis with dispersingof the dyestufl as. completely as possible in water, using a suitabledispersing agent, suchas sulfonated oils. The temperature of the dyebath during dyeing is kept e. g. around 70 C. and the period of dyeingranges in general from around one-half hour up to one hour. The quantityof dyestuffs to be used depends of course on the shade desired andranges in general from 1 to 4% of the weight of the material to be dyed.The concentration of the dye in the dye bath is of the order ofapproximately one-tenth 0! one per cent.

Cellulose acetate is dyed with the new dyes .a bright yellow color ofgood fastness.

I claim:

1. New azo dyestufis obtainable by coupling a diazotizedpara-substituted ortho-nitranilin, substituted in para position by amember of the roup consisting oi chlorine and methyl, with a compoundfrom the group consisting of the esters of acetone-oxalic acid andoxal-acetic acid. said dyes being valuable dyes for dyeing celluloseacetate. p

2. New azo dyestufl's obtainable by coupling a diazotizedpara-substituted ortho-nitranilin, substituted in para position by amember of the group consisting of chlorine and methyl, with alkyl estersof acetone oxalic acid, said dyes having the following general formula:RN=NR1, where R is the residue of the diazotized p-substitutedo-nitranilin and R1 is the residue of the alkyl ester of the acetoneoxalic acid, said dyes being valuable dyes for dyeing cellulose acetate.

3. New azo dyestufis obtainable by coupling a diazotizedpara-substituted ortho-nitranilin, substituted in para position by amember of the group consisting of chlorine and methyl, with ethylacetone oxalate, said dyes having the following general formula:R-N---N--R1, where R is the residue of the diazotized p-substitutedo-nitranilin and R1 is the residue of the ethyl acetone-oxalate, saiddyes being valuable dyes for dyeing cellulose acetate.

4. New azo dyestuffs obtainable by coupling a .diazotizedpara-substituted ortho-nitranilin, substituted in para position by amember of the group consisting of chlorine and methyl, with alkyl estersof oxal-acetic acid, said dyes having the following general formula:RN=NR1,

where R is the residue of the diazotized p-substituted o-nitranilin andR1 is the residue of the alkyl esterof oxal-acetic acid.

5. New azo dyestufis obtainable by coupling a of chlorine and methyl,with an alkyl ester of acetone oxalic acid.

7. The method of making new azo dyestufls which comprises coupling adiazotized parasubstituted ortho-nitranilin, substituted in paraposition with a member of the group consisting of chlorine and methyl,with ethyl acetoneoxalate.

8. The method of making new azo dyestuffs which comprises coupling adiazotized parasubstituted ortho-nitranilin, substituted in paraposition with a member of the group consisting of chlorine and methyl,with an alkyl ester or oxal-acetic acid.

9. The method of making new azo dyestuffs which comprises coupling adiazotized parasubstituted ortho-nitranilin, substituted in parapositionwith a member of the group consisting of chlorine and methyl, with ethyloxal-acetate.

10. The method of making new azo dyestufls' which comprises reacting adiazotized parasubstituted ortho-nitranilin, substituted in paraposition with a member of the group consisting of chlorine and methyl,with the sodio compound of an alkyl ester of acetone-oxalic acid.

11. The method of making new azo dyestufls which comprises reacting adiazotized parasubstituted ortho-nitranilin, substituted in paraposition with a member or the group consisting of chlorine and methyl,with the sodio compound of an alkyl ester or oxal-acetic acid.

12. The method 01' making new azo dyestuii's which comprises coupling adiazotized parasubstituted ortho-nitranilin, substituted in paraposition with a member of the group consisting of chlorine and methyl,with a compound iron:

til)

the group consisting oi the esters of acetoneoxalic acid and oral-aceticacid.

13. The method of dyeing cellulose acetate which comprises dyeing thesame with the new dyestufls defined in claim 1.

14. The method of dyeing cellulose acetate which comprises dyeing thesame with the new dyestuifs defined in claim 2.

15. The method of dyeing cellulose acetate which comprises dyeing thesame with the new dyestufls defined in claim 3.

16. The method of dyeing cellulose acetate which comprises dyeing thesame with the new dyestufls' defined in claim 4.

17. The method of dyeing cellulose acetate which comprises dyeing thesame with the new dyestufls defined in claim 5.

BERNARD HERSTEm.

CERTIFICATE OF CORRECTION. Patent No. 2,191,09LL. February 20; 191p.

BERNARD HERS TEIN.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 1,first column, line 50-51, strike out the words "compounds of the" andinsert the same before "acids;" in line 30; and that the said LettersPatent should be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 2nd day of April, A. D. 19110.

Henry Van Arsdale, .Acting Commissioner of Patents.

